The present invention relates generally to systems and methods for enabling vehicles to closely follow one another safely using automatic or partially automatic control. More particularly, the invention relates to systems and methods for maintaining a desired gap between vehicles.
In recent years significant strides have been made in the field of automated vehicle control. One segment of vehicle automation relates to vehicular convoying systems that enable vehicles to follow closely together in a safe, efficient and convenient manner. Following closely behind another vehicle has the potential for significant fuel savings benefits, but is generally unsafe when done manually by the driver. One type of vehicle convoying system is sometimes referred to as vehicle platooning in which a second, and potentially additional, vehicle(s) is/are automatically or semi-automatically controlled to closely follow a lead vehicle in a safe manner.
The fuel efficiency advantages of platooning are particularly noticeable in fields such as the trucking industry in which long distances tend to be traveled at highway speeds. One of the on-going challenges of vehicle platooning and convoying systems is controlling the gap between the platooning vehicles. The potential fuel economy gains generally improve the closer the platooning vehicle travel together. At the same time, the reaction time potentially available for responding to changes initiated by the lead vehicle is shortened as the gap shortens which can make the gap control more challenging. At times, braking may be required to prevent a trailing vehicle from getting too close to a leading vehicle. Frequent braking and/or the frequent use of other fuel inefficient gap control techniques can quickly erode the potential fuel efficiency advantages of platooning and convoying systems.
Although existing gap control techniques work well, there are continuing efforts to develop improved gap control methods and systems that provide safe and fuel efficient operation as well as a comfortable user experience. The present application describes techniques for controlling the gap between vehicles that are well suited for platooning, convoying and other automated or semi-automated driving applications.